Legal claims defining the scope of protection. Each claim is shown in both the original legal language and a plain English translation.
1. A circuit for selectively providing an alternating voltage to an AM-EWOD element electrode, the circuit having a memory element, an input node for connection to a source of an alternating voltage, an output node for connection to the AM-EWOD element electrode, and a first switch for addressing the output node by, in dependence on a data value stored in the memory element, any one of electrically connecting the input node to the output node and electrically isolating the input node from the output node; wherein the circuit is configured such that when the output node is electrically isolated from the input node, the output node is at a floating potential with the element electrode placed in a high impedance state.
This invention relates to a circuit for controlling the application of an alternating voltage to an active matrix electrowetting-on-dielectric (AM-EWOD) element electrode. The circuit addresses the challenge of selectively applying or isolating an alternating voltage to an AM-EWOD electrode while maintaining the electrode in a high-impedance state when isolated. The circuit includes a memory element that stores a data value, an input node connected to an alternating voltage source, and an output node connected to the AM-EWOD element electrode. A first switch controls the connection between the input and output nodes based on the stored data value. When the data value indicates activation, the switch connects the input node to the output node, applying the alternating voltage to the electrode. When the data value indicates deactivation, the switch isolates the input node from the output node, placing the output node and the connected electrode in a floating potential state with high impedance. The high-impedance state ensures minimal leakage current and prevents unintended voltage application, which is critical for precise control in AM-EWOD devices used in digital microfluidics. The memory element allows dynamic switching between active and high-impedance states, enabling flexible operation of the AM-EWOD system. The circuit design ensures reliable electrode control while maintaining system efficiency and performance.
2. A circuit as claimed in claim 1 , wherein the first switch is connected between the input node and the output node, a control terminal of the first switch being connected to an output of the memory element, wherein the first switch is a first transistor, and wherein the first transistor is of a low leakage design comprising a Lightly Doped Drain (LDD) transistor.
This invention relates to a low-leakage circuit design for reducing power consumption in electronic systems. The circuit addresses the problem of excessive current leakage in transistors, which is a significant issue in low-power applications such as portable devices and energy-efficient integrated circuits. The solution involves a transistor-based switch with a Lightly Doped Drain (LDD) structure to minimize leakage while maintaining reliable switching performance. The circuit includes an input node, an output node, and a memory element that stores a control signal. A first transistor, acting as a switch, is connected between the input and output nodes. The transistor's control terminal (gate) is linked to the memory element's output, enabling or disabling the connection based on the stored signal. The LDD design of the transistor reduces leakage current by creating a gradual doping profile in the drain region, which lowers the electric field and suppresses subthreshold leakage. This design is particularly useful in applications requiring long standby times or minimal power dissipation, such as IoT devices and battery-powered systems. The circuit ensures efficient power management while maintaining signal integrity during switching operations.
3. A circuit as claimed in claim 1 wherein the memory element comprises: a second switch connected between a data input and the control terminal of the first switch, a control terminal of the second switch being connected to a first control input; and a first capacitor connected between the control terminal of the first switch and a bias voltage.
This invention relates to a circuit design for memory elements, specifically addressing the need for stable and controllable memory storage in electronic circuits. The circuit includes a first switch, such as a transistor, which acts as the primary memory storage element by retaining a voltage state at its control terminal. To enhance functionality, the memory element further incorporates a second switch connected between a data input and the control terminal of the first switch. The second switch is controlled by a first control input, allowing selective data writing to the memory element. Additionally, a first capacitor is connected between the control terminal of the first switch and a bias voltage, ensuring the stored voltage remains stable over time. This configuration enables precise control over data storage and retrieval while maintaining the integrity of the stored state. The circuit is particularly useful in applications requiring low-power, non-volatile memory solutions, such as embedded systems or digital signal processing. The design ensures reliable operation by isolating the memory element from external noise and fluctuations, thereby improving overall system performance.
4. A circuit as claimed in claim 3 wherein the second switch is a second transistor.
A circuit is provided for managing power distribution in electronic systems, particularly addressing inefficiencies in power switching and control. The circuit includes a first transistor and a second transistor, where the second transistor functions as a switch to regulate current flow. The first transistor controls the primary power path, while the second transistor enhances switching efficiency by reducing power loss during transitions. The second transistor is configured to minimize voltage drop and heat generation, improving overall system performance. The circuit may be used in power management units, voltage regulators, or other applications requiring precise current control. The use of transistors as switches ensures fast response times and low energy consumption, addressing challenges in traditional mechanical or slower electronic switches. The design optimizes power delivery while maintaining stability and reliability in electronic devices.
5. A circuit as claimed in claim 1 wherein the memory element comprises: a second switch connected between a data input and the control terminal of the first switch, a control terminal of the second switch being connected to a first control input; and a first capacitor connected between the control terminal of the first switch and a bias voltage; wherein the second switch is a second transistor; and wherein the first transistor and the second transistor are transistors of the same channel type as one another.
This invention relates to a circuit design for memory elements, specifically addressing the need for stable and efficient data storage in integrated circuits. The circuit includes a first transistor acting as a primary switch, where the memory state is determined by the voltage at its control terminal. To enhance storage reliability, a second transistor is connected between a data input and the control terminal of the first transistor, allowing controlled data writing. The second transistor's control terminal is linked to a first control input, enabling selective activation for data transfer. A first capacitor is connected between the control terminal of the first transistor and a bias voltage, maintaining the stored data by preserving the voltage level when the second transistor is off. Both transistors are of the same channel type, ensuring consistent electrical behavior and simplifying fabrication. This design ensures robust data retention while allowing precise control over read and write operations, making it suitable for applications requiring low-power, high-density memory solutions. The use of matched transistors and a dedicated capacitor enhances stability and reduces leakage, addressing common challenges in semiconductor memory design.
6. A circuit as claimed in claim 1 and comprising a third switch connected between a source of the second alternating voltage and the output node, a control terminal of the third switch being connected to a second control input.
A circuit is provided for managing power distribution in electronic systems, particularly for handling alternating voltage sources. The circuit includes a first switch connected between a source of a first alternating voltage and an output node, and a second switch connected between a source of a second alternating voltage and the output node. The first and second switches are controlled by respective control inputs to selectively connect either voltage source to the output node. Additionally, a third switch is connected between the second alternating voltage source and the output node, with its control terminal linked to a second control input. This third switch allows for further control over the connection between the second voltage source and the output node, enabling more flexible power routing or redundancy. The circuit is designed to efficiently manage power distribution, ensuring stable and reliable operation by selectively activating or deactivating the switches based on input signals. This configuration is useful in applications requiring dynamic power management, such as in power supplies, voltage regulators, or backup power systems.
7. A circuit as claimed in claim 1 and comprising a second capacitor connected between the output node and a source of a bias voltage.
A circuit for managing electrical signals includes a first capacitor connected between an input node and an output node, where the first capacitor is configured to pass high-frequency signals while blocking direct current (DC) signals. The circuit also includes a second capacitor connected between the output node and a source of a bias voltage. The second capacitor provides a stable reference voltage at the output node, ensuring proper operation of downstream components while maintaining signal integrity. The combination of the first and second capacitors allows the circuit to filter and condition input signals, removing unwanted DC components while preserving high-frequency signal characteristics. This configuration is particularly useful in applications requiring precise signal processing, such as in communication systems, sensor interfaces, or analog front-end circuits. The second capacitor ensures that the output node remains at a controlled voltage level, preventing signal distortion or degradation due to DC offsets. The overall design enhances signal fidelity and reliability in electronic systems where accurate signal transmission is critical.
8. A circuit as claimed in claim 1 and comprising a third capacitor connected between the control terminal of the first switch and the input node, wherein the third capacitor has a voltage-dependent capacitance.
This invention relates to electronic circuits, specifically those involving switching elements and capacitive components. The problem addressed is improving the performance of circuits that use switches to control signal flow, particularly in applications where precise timing, low distortion, or high efficiency is required. The circuit includes a first switch with a control terminal, an input node, and an output node. The first switch is configured to selectively connect or disconnect the input node from the output node based on a control signal applied to the control terminal. A second capacitor is connected between the control terminal and the output node, and a third capacitor is connected between the control terminal and the input node. The third capacitor has a voltage-dependent capacitance, meaning its capacitance value changes in response to the voltage applied across it. The voltage-dependent third capacitor helps stabilize the control signal applied to the first switch, reducing unwanted variations in switching behavior. This can improve circuit reliability, reduce signal distortion, and enhance efficiency. The second capacitor provides feedback from the output node to the control terminal, further refining the switching characteristics. The combination of these elements allows for precise control over the switching operation, making the circuit suitable for high-performance applications such as signal processing, power conversion, or communication systems.
9. A circuit as claimed in claim 1 wherein the memory element comprises a static read-only memory (SRAM).
A circuit includes a memory element configured to store data and a control circuit coupled to the memory element. The control circuit is designed to receive a write command and, in response, generate a write signal to the memory element. The memory element is configured to store data in response to the write signal. The memory element comprises a static random-access memory (SRAM) that retains data as long as power is supplied. The SRAM is organized into multiple memory cells, each capable of storing one or more bits of data. The control circuit may include logic to manage read and write operations, ensuring data integrity and efficient access. The SRAM-based memory element provides fast read and write operations, low power consumption, and high reliability, making it suitable for applications requiring quick data access and retention. The circuit may be part of a larger system, such as a processor, microcontroller, or embedded system, where fast and reliable memory access is critical. The use of SRAM ensures data persistence during active operation, though it does not retain data when power is removed. This design addresses the need for high-speed, low-latency memory in digital systems where performance and reliability are prioritized.
10. A circuit as claimed in claim 1 and further comprising a sensor circuit connected between the output node and a sensing output node.
A circuit is provided for managing electrical signals, particularly in applications requiring precise signal conditioning or monitoring. The circuit includes an input node for receiving an electrical signal, an output node for providing a conditioned or processed version of the signal, and a sensor circuit connected between the output node and a sensing output node. The sensor circuit monitors the signal at the output node and provides a corresponding output at the sensing output node, enabling real-time feedback or control. The primary function of the circuit is to process an input signal, such as amplifying, filtering, or otherwise modifying it, while the sensor circuit allows for continuous observation of the processed signal. This configuration is useful in systems where signal integrity, stability, or performance must be verified dynamically, such as in power management, communication systems, or sensor interfaces. The sensor circuit may include components like comparators, analog-to-digital converters, or other monitoring elements to detect voltage, current, or other signal characteristics. The overall design ensures that the processed signal can be both utilized and monitored simultaneously, improving system reliability and adaptability.
11. An active matrix EWOD device having a plurality of AM-EWOD elements, each element having an element electrode and a reference electrode, the device comprising a reference electrode drive circuit for applying a first alternating voltage to the reference electrode and array element circuits for addressing the element electrode of a respective AM-EWOD element by any one of (i) applying a second alternating voltage to the element electrode and (ii) putting the element electrode of the respective AM-EWOD element in a high impedance state, wherein the second alternating voltage has the same frequency as the first alternating voltage and the second alternating voltage is out of phase with the first alternating voltage, wherein at least one of the array element circuits is an array element circuit as defined in claim 1 .
An active matrix electrowetting-on-dielectric (AM-EWOD) device is used for manipulating droplets of fluid on a substrate. The device addresses challenges in controlling droplet movement and stability by using an array of AM-EWOD elements, each with an element electrode and a reference electrode. The device includes a reference electrode drive circuit that applies a first alternating voltage to the reference electrode. Additionally, array element circuits control the element electrodes by either applying a second alternating voltage or placing the element electrode in a high impedance state. The second alternating voltage has the same frequency as the first but is out of phase with it. This configuration allows precise control over droplet actuation by selectively applying voltages or isolating electrodes. The array element circuits may include additional features, such as a drive transistor for applying the second alternating voltage and a switch transistor for setting the high impedance state, ensuring efficient droplet manipulation. The device enables dynamic fluid handling in applications like lab-on-a-chip systems, where precise droplet control is essential.
12. A circuit as claimed in claim 1 , further comprising a reference electrode spaced oppositely from the element electrode, wherein when the output node is electrically isolated from the input node, a voltage applied to the reference electrode is capacitively coupled to the element electrode when a droplet is present at the element electrode.
This invention relates to a circuit for droplet detection and manipulation, addressing the challenge of accurately sensing and controlling liquid droplets in microfluidic or lab-on-a-chip systems. The circuit includes an element electrode and an input node, where the element electrode interacts with a droplet to modulate an electrical signal. The circuit further incorporates a reference electrode positioned opposite the element electrode. When the output node is electrically isolated from the input node, a voltage applied to the reference electrode is capacitively coupled to the element electrode only when a droplet is present at the element electrode. This capacitive coupling enables precise detection of the droplet's presence and facilitates controlled manipulation of the droplet through electrical signals. The reference electrode's placement and the isolation of the output node ensure that the capacitive interaction is specific to the droplet, improving sensitivity and reducing interference. This design enhances the reliability of droplet-based assays and microfluidic operations by providing a clear electrical signal indicative of droplet presence, enabling real-time monitoring and automation in fluidic systems.
13. A circuit as claimed in claim 1 , wherein the input node further is connectable to a source of a second alternating voltage, and prior to the first switch switching from electrically connecting the input node to the output node to electrically isolating the input node from the output node, the second alternating voltage is applied to the output node to pre-charge the element electrode to the second alternating voltage.
This invention relates to a circuit designed to manage electrical connections and pre-charge an element electrode before switching operations. The circuit includes an input node, an output node, and a first switch that selectively connects or isolates the input node from the output node. The input node is also connectable to a source of a second alternating voltage. Before the first switch transitions from connecting to isolating the input and output nodes, the second alternating voltage is applied to the output node. This pre-charges the element electrode to the second alternating voltage, ensuring controlled voltage levels during switching operations. The circuit may also include a second switch that connects the output node to a reference potential, such as ground, when the first switch is isolating the input and output nodes. This configuration helps maintain stable voltage conditions and reduces transient effects during switching. The invention is particularly useful in applications requiring precise voltage control and minimal switching noise, such as in power electronics or signal processing circuits.
Unknown
May 26, 2020
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